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NLO QCD corrections to \( {\text{t}}\overline{\text{t}} {\text{b}}\overline{\text{b}} \) production at the LHC: 2. Full hadronic results. (English) Zbl 1271.81172
Summary: We present predictions for \( {\text{t}}\overline{\text{t}} {\text{b}}\overline{\text{b}} \) production at the LHC in next-to-leading order QCD. The precise description of this background process is a prerequisite to observe associated \( {\text{t}}\overline{\text{t}} {\text{H}} \) production in the \( {\text{H}} \to {\text{b}}\overline{\text{b}} \) decay channel and to directly measure the top-quark Yukawa coupling at the LHC. The leading-order cross section is extremely sensitive to scale variations. We observe that the traditional scale choice adopted in ATLAS simulations underestimates the \( {\text{t}}\overline{\text{t}} {\text{b}}\overline{\text{b}} \) background by a factor two and introduce a new dynamical scale that stabilizes the perturbative predictions. We study various kinematic distributions and observe that the corrections have little impact on their shapes if standard cuts are applied. In the regime of highly boosted Higgs bosons, which offers better perspectives to observe the \( {\text{t}}\overline{\text{t}} {\text{H}} \) signal, we find significant distortions of the kinematic distributions. The one-loop amplitudes are computed using process-independent algebraic manipulations of Feynman diagrams and numerical tensor reduction. We find that this approach provides very high numerical stability and CPU efficiency.

81V05 Strong interaction, including quantum chromodynamics
81U35 Inelastic and multichannel quantum scattering
81U99 Quantum scattering theory
81T15 Perturbative methods of renormalization applied to problems in quantum field theory
81T80 Simulation and numerical modelling (quantum field theory) (MSC2010)
Full Text: DOI
[1] ATLAS collaboration, ATLAS detector and physics performance technical design report, volume 2, CERN-LHCC-99-15 [ATLAS-TDR-15] [SPIRES].
[2] ATLAS collaboration, G. Aad et al., Expected performance of the ATLAS experiment — detector, trigger and physics, arXiv:0901.0512 [SPIRES].
[3] CMS collaboration; Bayatian, GL; etal., CMS technical design report, volume II: physics performance, J. Phys., G 34, 995, (2007)
[4] Kersevan, BP; Richter-Was, E., What is the \( Wb\overline b \), \( Zb\overline b \) or \( t\overline t b\overline b \) irreducible background to the light Higgs boson searches at LHC?, Eur. Phys. J., C 25, 379, (2002)
[5] Kersevan, BP; Richter-Was, E., The Monte Carlo event generator acermc version 1.0 with interfaces to PYTHIA 6.2 and HERWIG 6.3, Comput. Phys. Commun., 149, 142, (2003)
[6] J. Cammin and M. Schumacher, The ATLAS discovery potential for the channel\( t\overline t H \)\(,\)\( H → b\overline b \), ATL-PHYS-2003-024.
[7] V. Drollinger, T. Müller and D. Denegri, Searching for Higgs bosons in association with top quark pairs in the\( H0 → b\overline b \)decay mode, hep-ph/0111312 [SPIRES].
[8] S. Cucciarelli et al., Search for\( H0 → b\overline b \)in association with a\( t\overline t \)pair at CMS, CERN-CMS-NOTE-2006-119 [SPIRES].
[9] Benedetti, D.; etal., Observability of Higgs produced with top quarks and decaying to bottom quarks, J. Phys., G 34, n221, (2007)
[10] Butterworth, JM; Davison, AR; Rubin, M.; Salam, GP, Jet substructure as a new Higgs search channel at the LHC, Phys. Rev. Lett., 100, 242001, (2008)
[11] T. Plehn, G.P. Salam and M. Spannowsky, Fat jets for a light Higgs, arXiv:0910.5472 [SPIRES].
[12] Bredenstein, A.; Denner, A.; Dittmaier, S.; Pozzorini, S., NLO QCD corrections to top anti-top bottom anti-bottom production at the LHC: 1. quark-antiquark annihilation, JHEP, 08, 108, (2008)
[13] Bredenstein, A.; Denner, A.; Dittmaier, S.; Pozzorini, S., NLO QCD corrections to \( pp → t\overline t b\overline b + X \) at the LHC, Phys. Rev. Lett., 103, 012002, (2009)
[14] Bevilacqua, G.; Czakon, M.; Papadopoulos, CG; Pittau, R.; Worek, M., Assault on the NLO wishlist: \( pp → t\overline t b\overline b \), JHEP, 09, 109, (2009)
[15] Beenakker, W.; etal., Higgs radiation off top quarks at the tevatron and the LHC, Phys. Rev. Lett., 87, 201805, (2001)
[16] Dawson, S.; Orr, LH; Reina, L.; Wackeroth, D., Associated top quark Higgs boson production at the LHC, Phys. Rev., D 67, 071503, (2003)
[17] Dawson, S.; Jackson, C.; Orr, LH; Reina, L.; Wackeroth, D., Associated Higgs production with top quarks at the large hadron collider: NLO QCD corrections, Phys. Rev., D 68, 034022, (2003)
[18] Beenakker, W.; etal., NLO QCD corrections to \( t\overline t H \) production in hadron collisions, Nucl. Phys., B 653, 151, (2003)
[19] Dittmaier, S.; Uwer, P.; Weinzierl, S., NLO QCD corrections to \( t\overline t \) + jet production at hadron colliders, Phys. Rev. Lett., 98, 262002, (2007)
[20] Dittmaier, S.; Uwer, P.; Weinzierl, S., Hadronic top-quark pair production in association with a hard jet at next-to-leading order QCD: phenomenological studies for the tevatron and the LHC, Eur. Phys. J., C 59, 625, (2009)
[21] Lazopoulos, A.; McElmurry, T.; Melnikov, K.; Petriello, F., Next-to-leading order QCD corrections to \( t\overline t Z \) production at the LHC, Phys. Lett., B 666, 62, (2008)
[22] QCD, EW and Higgs Working Group collaborations, C. Buttar et al., Les Houches physics at TeV colliders 2005, standard model and Higgs working group: summary report, hep-ph/0604120 [SPIRES].
[23] NLO Multileg Working Group collaboration, Z. Bern et al., The NLO multileg working group: summary report, arXiv:0803.0494 [SPIRES].
[24] Ferroglia, A.; Passera, M.; Passarino, G.; Uccirati, S., All-purpose numerical evaluation of one-loop multi-leg Feynman diagrams, Nucl. Phys., B 650, 162, (2003)
[25] Denner, A.; Dittmaier, S., Reduction of one-loop tensor 5-point integrals, Nucl. Phys., B 658, 175, (2003)
[26] Denner, A.; Dittmaier, S., Reduction schemes for one-loop tensor integrals, Nucl. Phys., B 734, 62, (2006)
[27] Aguila, F.; Pittau, R., Recursive numerical calculus of one-loop tensor integrals, JHEP, 07, 017, (2004)
[28] Giele, WT; Glover, EWN, A calculational formalism for one-loop integrals, JHEP, 04, 029, (2004)
[29] Giele, W.; Glover, EWN; Zanderighi, G., Numerical evaluation of one-loop diagrams near exceptional momentum configurations, Nucl. Phys. (Proc. Suppl.), 135, 275, (2004)
[30] Ellis, RK; Giele, WT; Zanderighi, G., Semi-numerical evaluation of one-loop corrections, Phys. Rev., D 73, 014027, (2006)
[31] Binoth, T.; Guillet, JP; Heinrich, G.; Pilon, E.; Schubert, C., An algebraic/numerical formalism for one-loop multi-leg amplitudes, JHEP, 10, 015, (2005)
[32] Binoth, T.; Guillet, JP; Heinrich, G., Algebraic evaluation of rational polynomials in one-loop amplitudes, JHEP, 02, 013, (2007)
[33] Diakonidis, T.; etal., A complete reduction of one-loop tensor 5- and 6-point integrals, Phys. Rev., D 80, 036003, (2009)
[34] Diakonidis, T.; Fleischer, J.; Riemann, T.; Tausk, JB, A recursive reduction of tensor Feynman integrals, Phys. Lett., B 683, 69, (2010)
[35] Bern, Z.; Dixon, LJ; Dunbar, DC; Kosower, DA, Fusing gauge theory tree amplitudes into loop amplitudes, Nucl. Phys., B 435, 59, (1995)
[36] Berger, CF; Bern, Z.; Dixon, LJ; Forde, D.; Kosower, DA, Bootstrapping one-loop QCD amplitudes with general helicities, Phys. Rev., D 74, 036009, (2006)
[37] Bern, Z.; Dixon, LJ; Kosower, DA, On-shell methods in perturbative QCD, Ann. Phys., 322, 1587, (2007)
[38] Berger, CF; etal., An automated implementation of on-shell methods for one-loop amplitudes, Phys. Rev., D 78, 036003, (2008)
[39] Britto, R.; Cachazo, F.; Feng, B., Generalized unitarity and one-loop amplitudes in N = 4 super-Yang-Mills, Nucl. Phys., B 725, 275, (2005)
[40] Brandhuber, A.; McNamara, S.; Spence, BJ; Travaglini, G., Loop amplitudes in pure Yang-Mills from generalised unitarity, JHEP, 10, 011, (2005)
[41] Britto, R.; Feng, B.; Mastrolia, P., The cut-constructible part of QCD amplitudes, Phys. Rev., D 73, 105004, (2006)
[42] Forde, D., Direct extraction of one-loop integral coefficients, Phys. Rev., D 75, 125019, (2007)
[43] Badger, SD; Glover, EWN; Risager, K., One-loop phi-MHV amplitudes using the unitarity bootstrap, JHEP, 07, 066, (2007)
[44] Anastasiou, C.; Britto, R.; Feng, B.; Kunszt, Z.; Mastrolia, P., Unitarity cuts and reduction to master integrals in d dimensions for one-loop amplitudes, JHEP, 03, 111, (2007)
[45] Giele, WT; Kunszt, Z.; Melnikov, K., Full one-loop amplitudes from tree amplitudes, JHEP, 04, 049, (2008)
[46] Ellis, RK; Giele, WT; Kunszt, Z.; Melnikov, K., Masses, fermions and generalized D-dimensional unitarity, Nucl. Phys., B 822, 270, (2009)
[47] Ossola, G.; Papadopoulos, CG; Pittau, R., Reducing full one-loop amplitudes to scalar integrals at the integrand level, Nucl. Phys., B 763, 147, (2007)
[48] Mastrolia, P.; Ossola, G.; Papadopoulos, CG; Pittau, R., Optimizing the reduction of one-loop amplitudes, JHEP, 06, 030, (2008)
[49] Draggiotis, P.; Garzelli, MV; Papadopoulos, CG; Pittau, R., Feynman rules for the rational part of the QCD 1-loop amplitudes, JHEP, 04, 072, (2009)
[50] Hameren, A.; Papadopoulos, CG; Pittau, R., Automated one-loop calculations: a proof of concept, JHEP, 09, 106, (2009)
[51] Keith Ellis, R.; Melnikov, K.; Zanderighi, G., W+3 jet production at the tevatron, Phys. Rev., D 80, 094002, (2009)
[52] Berger, CF; etal., Next-to-leading order QCD predictions for W+3-jet distributions at hadron colliders, Phys. Rev., D 80, 074036, (2009)
[53] T. Binoth et al., Next-to-leading order QCD corrections to\( pp → b\overline b b\overline b + X \)at the LHC: the quark induced case, arXiv:0910.4379 [SPIRES].
[54] Cafarella, A.; Papadopoulos, CG; Worek, M., Helac-phegas: a generator for all parton level processes, Comput. Phys. Commun., 180, 1941, (2009)
[55] Czakon, M.; Papadopoulos, CG; Worek, M., Polarizing the dipoles, JHEP, 08, 085, (2009)
[56] Catani, S.; Seymour, MH, A general algorithm for calculating jet cross sections in NLO QCD, Nucl. Phys., B 485, 291, (1997)
[57] Dittmaier, S., A general approach to photon radiation off fermions, Nucl. Phys., B 565, 69, (2000)
[58] Phaf, L.; Weinzierl, S., Dipole formalism with heavy fermions, JHEP, 04, 006, (2001)
[59] Catani, S.; Dittmaier, S.; Seymour, MH; Trócsányi, Z., The dipole formalism for next-to-leading order QCD calculations with massive partons, Nucl. Phys., B 627, 189, (2002)
[60] Berends, FA; Pittau, R.; Kleiss, R., All electroweak four fermion processes in electron-positron collisions, Nucl. Phys., B 424, 308, (1994)
[61] Berends, FA; Pittau, R.; Kleiss, R., Excalibur: a Monte Carlo program to evaluate all four fermion processes at LEP-200 and beyond, Comput. Phys. Commun., 85, 437, (1995)
[62] Berends, FA; Daverveldt, PH; Kleiss, R., Complete lowest order calculations for four lepton final states in electron-positron collisions, Nucl. Phys., B 253, 441, (1985)
[63] Hilgart, J.; Kleiss, R.; Diberder, F., An electroweak Monte Carlo for four fermion production, Comput. Phys. Commun., 75, 191, (1993)
[64] Denner, A.; Dittmaier, S.; Roth, M.; Wackeroth, D., Predictions for all processes e\^{}{+}e− → 4 fermions + γ, Nucl. Phys., B 560, 33, (1999)
[65] Denner, A.; Dittmaier, S.; Roth, M.; Wackeroth, D., RACOONWW 1.3: a Monte Carlo program for four-fermion production at e\^{}{+}e\^{}{−} colliders, Comput. Phys. Commun., 153, 462, (2003)
[66] Dittmaier, S.; Roth, M., LUSIFER: A lucid approach to six fermion production, Nucl. Phys., B 642, 307, (2002)
[67] Hahn, T.; Pérez-Victoria, M., Automatized one-loop calculations in four and D dimensions, Comput. Phys. Commun., 118, 153, (1999)
[68] Hahn, T., Automatic loop calculations with feynarts, formcalc and looptools, Nucl. Phys. (Proc. Suppl.), 89, 231, (2000)
[69] Küblbeck, J.; Böhm, M.; Denner, A., Feynarts: computer algebraic generation of Feynman graphs and amplitudes, Comput. Phys. Commun., 60, 165, (1990)
[70] H. Eck and J. Küblbeck, Guide to FeynArts 1.0, University of Würzburg, Würzburg Germany (1992).
[71] Hahn, T., Generating Feynman diagrams and amplitudes with feynarts 3, Comput. Phys. Commun., 140, 418, (2001)
[72] Melrose, DB, Reduction of Feynman diagrams, Nuovo Cim., A 40, 181, (1965)
[73] Passarino, G.; Veltman, MJG, One loop corrections for e\^{}{+}e\^{}{−} annihilation into μ\^{}{+}μ\^{}{−} in the Weinberg model, Nucl. Phys., B 160, 151, (1979)
[74] Lei, G.; Wen-Gan, M.; Liang, H.; Ren-You, Z.; Yi, J., QCD corrections to \( t\overline t b\overline b \) productions via photon-photon collisions at linear colliders, Phys. Lett., B 654, 13, (2007)
[75] Hooft, G. ’t; Veltman, MJG, Scalar one loop integrals, Nucl. Phys., B 153, 365, (1979)
[76] Beenakker, W.; Denner, A., Infrared divergent scalar box integrals with applications in the electroweak standard model, Nucl. Phys., B 338, 349, (1990)
[77] Denner, A.; Nierste, U.; Scharf, R., A compact expression for the scalar one loop four point function, Nucl. Phys., B 367, 637, (1991)
[78] Dittmaier, S., Separation of soft and collinear singularities from one-loop N-point integrals, Nucl. Phys., B 675, 447, (2003)
[79] Denner, A.; Dittmaier, S.; Roth, M.; Wieders, LH, Electroweak corrections to charged-current e\^{}{+}e\^{}{−} → 4 fermion processes: technical details and further results, Nucl. Phys., B 724, 247, (2005)
[80] Stelzer, T.; Long, WF, Automatic generation of tree level helicity amplitudes, Comput. Phys. Commun., 81, 357, (1994)
[81] Alwall, J.; etal., Madgraph/madevent v4: the new web generation, JHEP, 09, 028, (2007)
[82] Dittmaier, S., Weyl-Van-der-Waerden formalism for helicity amplitudes of massive particles, Phys. Rev., D 59, 016007, (1999)
[83] Berends, FA; Giele, WT, Recursive calculations for processes with n gluons, Nucl. Phys., B 306, 759, (1988)
[84] Caravaglios, F.; Moretti, M., An algorithm to compute Born scattering amplitudes without Feynman graphs, Phys. Lett., B 358, 332, (1995)
[85] Draggiotis, P.; Kleiss, RHP; Papadopoulos, CG, On the computation of multigluon amplitudes, Phys. Lett., B 439, 157, (1998)
[86] Frederix, R.; Gehrmann, T.; Greiner, N., Automation of the dipole subtraction method in madgraph/madevent, JHEP, 09, 122, (2008)
[87] Bredenstein, A.; Dittmaier, S.; Roth, M., Four-fermion production at gamma gamma colliders. II: radiative corrections in double-pole approximation, Eur. Phys. J., C 44, 27, (2005)
[88] Ciccolini, M.; Denner, A.; Dittmaier, S., Strong and electroweak corrections to the production of Higgs+2 jets via weak interactions at the LHC, Phys. Rev. Lett., 99, 161803, (2007)
[89] Ciccolini, M.; Denner, A.; Dittmaier, S., Electroweak and QCD corrections to Higgs production via vector-boson fusion at the LHC, Phys. Rev., D 77, 013002, (2008)
[90] Gleisberg, T.; etal., SHERPA 1.α, a proof-of-concept version, JHEP, 02, 056, (2004)
[91] Tevatron Electroweak Working Group collaboration, A combination of CDF and D0 results on the mass of the top quark, arXiv:0803.1683 [SPIRES].
[92] Catani, S.; Dokshitzer, YL; Webber, BR, The K\^{}{−} perpendicular clustering algorithm for jets in deep inelastic scattering and hadron collisions, Phys. Lett., B 285, 291, (1992)
[93] G.C. Blazey et al., Run II jet physics, in Proceedings of the Physics at RUN II: QCD and Weak Boson Physics Workshop, Batavia U.S.A. November 4-6 1999, pg. 47 [hep-ex/0005012] [SPIRES].
[94] Pumplin, J.; etal., New generation of parton distributions with uncertainties from global QCD analysis, JHEP, 07, 012, (2002)
[95] Stump, D.; etal., Inclusive jet production, parton distributions and the search for new physics, JHEP, 10, 046, (2003)
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